diff options
| author | Alexander Duyck <alexander.h.duyck@intel.com> | 2012-04-25 04:36:38 +0000 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2012-05-09 22:31:44 -0700 |
| commit | 3ebe8fdeb043e8c630cac6dc90d483e729e17017 (patch) | |
| tree | d4f16a8ac2bb88460cf817477d5acb4a3e18f54d /drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | |
| parent | 943561d3e7f82645aafb65839feb9f99e2718bac (diff) | |
ixgbe: Set Drop_EN bit when multiple Rx queues are present w/o flow control
The drop enable bit can be used to improve the performance of the adapter
in the case of multiple queues being present. This performance gain is due
to the fact that some slower CPUs can cause the FIFO to backfill preventing
faster CPUs from receiving additional work. By setting the drop enable bit
we prevent this and instead just drop the packets that would have been
bound for the slower CPU.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/ixgbe/ixgbe_main.c')
| -rw-r--r-- | drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 59 |
1 files changed, 58 insertions, 1 deletions
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 0915e77cf375..1693ec3d4046 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -2771,6 +2771,61 @@ static void ixgbe_configure_tx(struct ixgbe_adapter *adapter) ixgbe_configure_tx_ring(adapter, adapter->tx_ring[i]); } +static void ixgbe_enable_rx_drop(struct ixgbe_adapter *adapter, + struct ixgbe_ring *ring) +{ + struct ixgbe_hw *hw = &adapter->hw; + u8 reg_idx = ring->reg_idx; + u32 srrctl = IXGBE_READ_REG(hw, IXGBE_SRRCTL(reg_idx)); + + srrctl |= IXGBE_SRRCTL_DROP_EN; + + IXGBE_WRITE_REG(hw, IXGBE_SRRCTL(reg_idx), srrctl); +} + +static void ixgbe_disable_rx_drop(struct ixgbe_adapter *adapter, + struct ixgbe_ring *ring) +{ + struct ixgbe_hw *hw = &adapter->hw; + u8 reg_idx = ring->reg_idx; + u32 srrctl = IXGBE_READ_REG(hw, IXGBE_SRRCTL(reg_idx)); + + srrctl &= ~IXGBE_SRRCTL_DROP_EN; + + IXGBE_WRITE_REG(hw, IXGBE_SRRCTL(reg_idx), srrctl); +} + +#ifdef CONFIG_IXGBE_DCB +void ixgbe_set_rx_drop_en(struct ixgbe_adapter *adapter) +#else +static void ixgbe_set_rx_drop_en(struct ixgbe_adapter *adapter) +#endif +{ + int i; + bool pfc_en = adapter->dcb_cfg.pfc_mode_enable; + + if (adapter->ixgbe_ieee_pfc) + pfc_en |= !!(adapter->ixgbe_ieee_pfc->pfc_en); + + /* + * We should set the drop enable bit if: + * SR-IOV is enabled + * or + * Number of Rx queues > 1 and flow control is disabled + * + * This allows us to avoid head of line blocking for security + * and performance reasons. + */ + if (adapter->num_vfs || (adapter->num_rx_queues > 1 && + !(adapter->hw.fc.current_mode & ixgbe_fc_tx_pause) && !pfc_en)) { + for (i = 0; i < adapter->num_rx_queues; i++) + ixgbe_enable_rx_drop(adapter, adapter->rx_ring[i]); + } else { + for (i = 0; i < adapter->num_rx_queues; i++) + ixgbe_disable_rx_drop(adapter, adapter->rx_ring[i]); + } +} + #define IXGBE_SRRCTL_BSIZEHDRSIZE_SHIFT 2 static void ixgbe_configure_srrctl(struct ixgbe_adapter *adapter, @@ -5276,8 +5331,10 @@ static void ixgbe_watchdog_update_link(struct ixgbe_adapter *adapter) if (adapter->ixgbe_ieee_pfc) pfc_en |= !!(adapter->ixgbe_ieee_pfc->pfc_en); - if (link_up && !((adapter->flags & IXGBE_FLAG_DCB_ENABLED) && pfc_en)) + if (link_up && !((adapter->flags & IXGBE_FLAG_DCB_ENABLED) && pfc_en)) { hw->mac.ops.fc_enable(hw); + ixgbe_set_rx_drop_en(adapter); + } if (link_up || time_after(jiffies, (adapter->link_check_timeout + |